How I Switched Terminal Apps Without Interrupting 10+ Running Sessions

Terminal.app had been my default for years, but the Korean text rendering bugs were getting worse, I needed proper split panes, and better features for managing AI coding agents. So I moved to iTerm2 — then discovered cmux, a terminal built specifically for AI agent workflows.

The thing I worried about most? I had over 10 Claude Code conversations running across two Mac Minis. If those sessions closed, I’d lose the entire task flow — context, history, everything mid-process. That’s not something you can just restart.

Turns out, tmux solved all of it.

tmux doesn’t care about your terminal app

tmux runs as a background process. Terminal.app, iTerm2, cmux — these are just viewers. The sessions keep running regardless of which app you use to look at them.

I closed Terminal.app, opened cmux, and typed:

tmux ls
tmux attach -t aibot-01

All 10+ Claude sessions were right there. Windows, panes, running agents — all intact. The blog pipeline that had been generating posts for 6 hours didn’t skip a beat.

Why Terminal.app → iTerm2 → cmux

• Terminal.app — Korean text rendering bugs, no split panes
• iTerm2 — better, but still a general-purpose terminal
• cmux — vertical tabs, agent notifications, built-in browser, designed for AI workflows

The commands you need

• tmux ls — list all sessions
• tmux attach -t name — reconnect to a session
• Ctrl+B d — detach without killing anything
• tmux new -s name — create a named session

That’s it. Switch terminal apps anytime — tmux keeps everything alive. Zero downtime, zero lost context.